SU108019A1 - Device to prevent steam boiler re-circulation - Google Patents

Description

In the operation of steam boilers there are two positions of the water level, which cause an emergency power failure of the boiler.

The first position is the re-feed of the boiler with water and throwing it into the superheater, followed by a drop in the overheating temperature and the threat of water being thrown into the turbine. The second position is the water leakage leading to the burnout of the heating surfaces of the boiler.

There are various devices that ensure its operation at the start of water.

Also known are devices for preventing the steam boiler from reproducing, made in the form of a column connected by pipes to the water and steam spaces of the boiler and with a float in it that closes the electrical circuit, opening the tap on the drainage line of the boiler.

However, these devices are semi-automatic, in particular, the valve on the drainage pipe, after opening with a float, requires manual closing.

The described device is a further improvement of the known devices of this kind. In it, both the opening and the closing of the drain valve are performed automatically without the intervention of the operating personnel. The upper end of the drainage pipe, located in the boiler drum, is above the lowest water level in the boiler, which eliminates excessive water drop in it.

The drawing shows a diagram of the device.

The automatic device is designed to prevent both the water leakage and the re-circulation of the steam boiler in the event of a power failure. The device includes: a drain valve / installed on the drain pipe 2 of the steam boiler 5, - supplied with a hydraulic drive 4; a needle valve 5 with a solenoid actuator 6 connecting the hydraulic actuator 4 to the feed pipe 7; contact mercury differential meter 8, attached to

the receiving vessel I, which, in turn, is connected by two pipelines 10 to the water and steam spaces of the boiler 3, and two relays // and 12.

The contact contact of the manometer 8 flowing under the influence of the moving water level in the boiler 3 closes the alternating current circuit to ground. In the case of water missing, mercury closes the circuit on the minus side, which causes the tripping relay to operate, and as a result, the electric motors of the fueling furnace are switched off by fuel (not shown in the drawing). When repacking the boiler, a contact on the plus side is activated, then the contact differential pressure meter 8 switches on the relay 12 and opens the needle valve 5 having the hydraulic pressure supply from supply pipes 7 through the solenoid actuator 6 through the check valves 13. Under the action of hydraulic pressure, the drain valve 1 opens 3 excess water from the boiler. The drain pipe 2 has a bell, the edges of which are at a mark located above the lower acceptable level. Therefore, the water from the boiler can only be reset to this mark.

The commencement of lowering the excess level is terminated by a break.

the command circuit of the contact differential gauge, and the hydraulic actuator 4 under the action of the spring 14 begins to slowly close the drain valve /, since water

from the hydraulic actuator goes through the throttle valve / 5 to the drainage. ,

11 p c dme t and 3 o brete n i

Claims (2)

1- A device for the prevention of the steam boiler reflux, including a column connected to the steam and water spaces of the boiler and a drain pipe with a valve that opens automatically when the boiler is repaired, a mechanism connected to the column, in order to automate the entire reset process izlischka water from the boiler by opening and then closing the drain valve, the column is equipped with a contact mercury differential pressure gauge, the closure and opening of the contacts of which opens or closes the drain valve using a hydraulic drive. 2. Use in the device according to claim 1 drainage pipe, the mouth of which is located in the boiler, the lowest permissible water level in the boiler.